It is known in the art of molding to provide a post-mold system as an extension of an overall molding system for providing conditioning (i.e. heating or more commonly cooling) of a molded article after it has been removed from a mold within which it was produced.
A typical post-mold-system includes a retrieval device for retrieving the molded article from the mold and for conditioning it thereafter. The conditioning provided to the molded article in the retrieval device is usually to cool it outside of the mold until it reaches a form stable temperature. A technical effect of the foregoing is to reduce the amount of in-mold cooling time and thereby reduce the overall time required to perform a complete molding cycle. A typical retrieval device includes a receptacle for the molded article that is defined in a tubular body. The tubular body is also configured to define a circulation channel for the circulation of cooled water, whereby the molded article may be cooled within the receptacle by means of conduction cooling. To accommodate movement of the receptacle in retrieving the molded article from the open mold, the receptacle is fixed to a carrier that is mounted to a movement structure such as a programmable robot. The carrier also provides a means for connecting the circulation channel to a source and sink of coolant.
An example of the foregoing retrieval device may be referenced in commonly assigned U.S. patent RE33,237 to Delfer, published on Jun. 19, 1990. In particular, the patent discloses a carrier plate cooperating with an injection molding machine and having at least two sets of cavities therein for cooling the hollow plastic articles, with the number of cavities corresponding to a multiple of at least two times the number of hollow plastic articles produced in an injection molding cycle. The apparatus also includes means for aligning one set at a time of said carrier plate cavities to juxtapose said set of cavities with the hollow plastic articles formed in an injection molding cycle, and means for transferring said hollow plastic articles to said juxtaposed cavities
The typical post-mold system may also include additional conditioning devices to further accelerate the cooling of the molded article and/or to deal with specific conditioning requirements thereof (e.g. focused cooling of relatively warm regions of the molded article).
An example of such a post-mold system may be referenced in commonly assigned U.S. Pat. No. 6,558,598 to Neter, published on May 6, 2003, which discloses an improved method and apparatus for injection molding and cooling molded articles such as preforms so as to avoid crystallinity. The apparatus and method make use of a take-off plate (i.e. retrieval device) for removing articles from a mold, which plate may include heat transfer devices for cooling exterior surfaces of the molded articles or preforms, and a system (i.e. additional conditioning device) for cooling in a controlled manner interior surfaces of the molded articles or preforms. The additional conditioning device is provided as cooling pins for expelling coolant, such as air, on relatively high-heat regions of the molded article.
Another example of such a post-mold system is provided in commonly assigned U.S. Pat. No. 6,770,239 to Oueslati, published on Aug. 3, 2004. The difference to the foregoing is that the cooling pin is inserted into the preform such that it makes contact with targeted area, such as the mold gate area, for providing conductive cooling thereto.
Of a rather different design than the foregoing is a post-mold system as described in US patent application publication 2009/0297648 to Sicilia, published on Dec. 3, 2009. The post-mold system includes an end of arm tool (i.e. retrieval device) that transfers the molded preforms from the mold to a temperature conditioning station (i.e. additional conditioning stations) having a conveyor. The batch of molded preforms is received and retained on the end of arm tool by an array of cooling tubes that are attached to a number of identical cooling tubes carrier devices. The conveyor is adapted to receive the carrier devices and the cooling tubes loaded with molded preforms from the end of arm tool. The conveyor is also adapted to transfer rapidly the carrier devices and the empty cooling tubes into the end of arm tool before the end of arm tool is moved back into the molding area to receive subsequent batches of molded preforms.
Also of note is US patent application publication 2009/0212459 to Neter, published on Aug. 27, 2009 which discloses a system for the post-treatment of preforms produced in an injection molding mold, comprising at least two post-treatment tools which each have a receiving plate which has a group of receiving cavities and a pin plate which has a group of post-treatment pins, and a device for transferring the preforms from the injection molding mold alternately into the at least two post-treatment tools. In order to provide a method of and a system for the post-treatment of preforms produced in an injection molding mold, which on the one hand allows early removal of the preform from the injection molding tool and which on the other hand allows reliable post-treatment in particular of the interior of the preform after removal from the injection molding mold, it is proposed in accordance with the invention that the post-treatment pins remain in the preforms for a period of time which is longer than the mold stand time